Improving Interface Quality of 4H-SiC MOS Devices with High Temperature Oxidation Process in Mass Produce Furnace

A high-temperature process is used to enhance the COx desorption rate to reduce trap density in SiC/SiO2 interface for SiC MOSFETs. Interface state density as measured by Terman method and C-ψs method for the oxidation processes at a high temperature of 1350°C show significant improvement compared to traditional Si thermal oxidation temperature of 1200°C. The higher oxidation temperature led to a much faster growth rate and some observable hysteresis in the CV curves, which could be due to electron trap and can be resolved by NOx post oxidation anneal (POA).